OBJECTIVES: (a) To synthesize the stereoisomers and labeled forms of certain tetrahydroisoquinolines which have not yet been made, for the purposes of our own work and others. (b) To elucidate the major metabolic pathways of tetrahydroisoquinolines which may form in vivo from aldehydes. (c) To continue studies on the effects of tetrahydroisoquinolines, given centrally to rats and mice, on the levels, metabolism and turnover of biogenic amines. (d) To rigorously examine neural tissues and fluids of alcohol-dependent rats and mice for tetrahydroisoquinolines derived from dopamine and noradrenaline, and for their principal metabolites, using electron capture gas chromatography, and liquid chromatography with electrochemical detection; new products will be definitively identified by GC/mass spectrometry.